NATO was virtually entirely a mutual defense pact vs Russia in their previous incarnation as the USSR.
This “defense pact” has invaded, bombed and destroyed many countries within only my lifetime, it’s a laughable statement unless your historical horizon is less than a decade.
Living in America it’s incredible to me how people I run into don’t even know the countries that their own government has invaded using its “defense pact”, or pay attention to people whose lives they’ve ruined, and thus can’t even understand why people see them as a threat.